There's no car that everyone is happy with, and that has no problems. Pick any make and model you like, do a google search for problems, and you'll see any number of message boards etc. where people moan about the car in question. (Nobody ever goes on those boards to say they're happy and have no problems, so you always see a distorted view.)
I'm a Merc man myself, but I'm happy to acknowledge that Audi is a great car, well built (in fact probably better built than MB!) and on the whole reliable. I happen to think it's a bit boring and insipid myself, but that's just my opinion. Still, if you haven't already done so, I would go and test drive the A4 as well as the BMW 3-series and Merc C-class equivalents, then you'll at least know which one you like best.
If you do go for the A4, then I'm a huge fan of the Quattro, so would go for that personally if money (purchase price as well as running costs) is no object.
One thing you should definitely do is pay more attention to what you are trying to purchase. How is it you're trying to purchase a car from a dealer, a used 2009 but you don't know what model the car is? Go figure out exactly what car you are looking at. Research the values online using www.kbb.com, www.nadaguides.com and www.clearbook.truecar.com to come up with an average value and then have the car inspected by your own trusted independent Audi shop or technician via a Pre Purchase Inspection.
The A4 is an expensive car to own - the fuel consumption, insurance and repair/maintenance costs are high.
If you don't have to pay for any of it, it's a nice car to drive. If you are responsible for everything, let's hope you have lots of disposable income.
Consider an Infiniti? Just as nice, better economy and cheaper running costs.
Love them until they get over 100K miles. Then you'd better have a fat wallet because the repairs cost an arm and leg. Lexus/Infinity FAR more reliable over its entire life
Stpaul guy posted PICTURES of a VW engine with LEAKING hoses in it! THat was GREEN PRESTONE COOLANT<> a VW/AUDI no-no! AUDIs have SPECIAL RULES and VALVOLINE and PRESTONE wil will them! They are FULL racing engines requiring only 5-02/505 rated FULL SYTH EUROPEAN OILS and ALL fluids came from either RAVENOL or PENTOC+SYNTH companies of GERMANY! A RE$AL AUDI oil change is good for TWO FULL YEARS unlimited miles! It is ALWAYS a GM trained person or OIL CHANGE CENTER or PEP BOYS that ruins nearly AN european car, and ESPECIALLY an AUDI CAR! PENNZOIL ULTRA EURO oil gives a 15 year 500k mile WARRANTy against ENGINE TROUBLES and TURBO woes, and even LEAKS and SEALS issues! SCOT is ALSO out of his league here as well Stpaul guy is OUT OF HIS LEAGUE HERE! INSURANCE DROPS because AUDI cars hardly EVER have accidents! MINE dropped by 35%! hey are the BEST balance between POWER and ECONOMY nearly anywhere unless you want a NISSAN or TOYOTA! Many AUDIS even have SONAR and RADAR in them for accident avoidance and they will NEVER EVER RUST or even need to be WAXED even! They are the TOp of the AUTO FOOD CHAIN and nearly EVERY RACE entered by AUDI< earns an AUDI WIN! even in AIRPLANE races! AUDIS are the BEST of the GERMAN BIG THREE
I like them.
How much money do you have?